In a manufacturing process of a semiconductor device, a plasma processing apparatus has been used which performs a processing (e.g., etching) on a processing target substrate (e.g., a semiconductor wafer) by applying plasma of a processing gas to the processing target substrate. Conventionally, a capacitively coupled plasma etching apparatus has been widely used for single wafer type plasma etching.
Generally, in the capacitively coupled plasma etching apparatus, an upper electrode and a lower electrode are disposed in parallel within a processing container configured as a vacuum chamber, a semiconductor wafer is placed on the upper electrode, and then, a high frequency power is applied between both electrodes. Then, plasma is generated by a high frequency discharge between both electrodes, so that an etching processing is performed on the surface of the substrate in a desired pattern by radicals or ions in the plasma.
Conventionally, in order to control a plasma density distribution mainly in the processing container, the capacitively coupled plasma etching apparatus includes a magnetic field forming mechanism that forms a magnetic field or a magnetic force line passing through a processing space in the processing container on a predetermined route.
For example, Patent Document 1 discloses a magnetic field forming mechanism configured to form a uniform horizontal magnetic field in a processing space within a processing container by arranging a plurality of dipole ring magnets each made of an anisotropic segment pillar magnet annularly around (outside) a sidewall of the processing container. Patent Document 2 discloses a magnetic field forming mechanism configured to form a uniform horizontal magnetic field in a processing space within a processing container by arranging, above a ceiling of the processing container, a rotary magnet having N and S poles sufficiently farther away from each other than a diameter size of a processing target substrate, and rotating the rotary magnet around a central axis of the processing container as a rotary center. Further, Patent Document 3 discloses a magnetic field forming mechanism configured to form a radial magnetic field in a processing space within a processing container by arranging a plurality of electromagnets each having N and S poles standing in a vertical direction.